On Monday, the first day of the Epic-Apple trial, we learned that Epic had made a curious pitch for a Sony VR game. Yesterday’s proceedings revealed something quite different: AR’s rise influenced Epic’s decision to fight Apple. That suggests Epic may be anxious about holding onto its content edge in AR.

During the cross examination of Epic CEO Tim Sweeney, Apple’s lawyers presented a document from Epic concerning its plan (dubbed “Project Liberty”) to challenge both Apple and Google over what Epic calls “the anti-competitive 30% tax” on mobile platforms. In the document, Epic included AR on a list of reasons for launching its offensive, saying it had to “solve this problem” of the 30% revenue split before AR tech takes off and the rate settles there.